*{
    box-sizing: border-box;
}
body{
    margin: 0;
    padding: 0;
    font-family: Verdana, Geneva, Tahoma, sans-serif;
    font-size: 14px;
}
header{
    height: 50px;
    line-height: 50px;
    text-align: center;
    color: white;
    background: gray;
    font-size: 18px;
    font-weight: bold;
    /*word-spacing只能控制英文*/
    /*word-spacing: 10px;*/
}
main{
    padding: 10px;
}
form{
    width: 100%;
    /*border: 1px solid red;*/
}
input{
    display: block;
    height: 40px;
    margin-top: 5px;
    width: 100%;
    padding-left: 5px;
}
input[type=submit]{
    color: white;
    font-size: 18px;
    font-weight: bold;
    background: gray;
    border: 1px solid gray;
}
section{
    display: none;
}
dt{
    margin: 5px auto;
    float: left;
}
dd{
    margin: 5px auto;
    float: right;
}
.clear{
    clear: both;
}
hr{
    clear: both;
}
.color{
    color: red;
}